PT 795 Hand Intrinsics

Question 1

Thenar: Opponens pollicis m.

Answer 1

scaphoid and trapezium tubercles
lateral 1st MC
recurrent branch of median nerve
C8, T1
thumb opposition => draws 1st MC medially to center of palm and rotates medially

Question 2

Thenar: abductor pollicis brevis m.

Answer 2

scaphoid and trapezium tubercles
base of proximal phalanx
recurrent branch of median nerve
C8, T1
abducts thumb, helps oppose it

Question 3

Thenar: flexor pollcis brevis m. (superficial head)

Answer 3

scaphoid and trapezium tubercles
base of proximal phalanx
recurrent branch of median nerve
C8, T1
thumb flexion

Question 4

Thenar: flexor pollicis brevis m. (deep head)

Answer 4

scaphoid and trapezium tubercles
lateral base of proximal phalanx
deep branch of ulnar nerve
C8, T1
thumb flexion

Question 5

Thenar: adductor pollicis m. (oblique head)

Answer 5

base of 2nd, 3rd MC, capitate, adjacent carpals
medial base of proximal phalanx
deep branch of ulnar nerve
C8, T1
thumb adduction

Question 6

Thenar: adductor pollicis m. (transverse head)

Answer 6

anterior shaft of 3rd MC
medial base of proximal phalanx
deep branch of ulnar nerve
C8, T1
thumb adduction

Question 7

Hypothenar: abductor digiti minimi m.

Answer 7

pisiform
medial base of proximal phalanx of 5th digit
deep branch of ulnar nerve
C8, T1
5th finger abduction, assists flexion of proximal phalanx

Question 8

Hypothenar: flexor digiti minimi brevis m.

Answer 8

hook of hamate and flexor retinaculum
medial base of proximal phalanx of 5th digit
deep branch of ulnar nerve
C8, T1
5th finger proximal phalanx flexion

Question 9

Hypothenar: opponens digiti minimi m.

Answer 9

hook of hamate
MC 5 medial border
deep branch of ulnar nerve
C8, T1
draws MC 5 anterior and rotates it, brings 5th finger into opposition with thumb

Question 10

Lumbricals m: 1 and 2

Answer 10

lateral 2 tendons of flexor digitorum profundus (unipennate muscles)
extensor expansion of fingers 2-5
median nerve
C8, T1
flex MCP joints, extend IP joints of fingers 2-5

Question 11

Lumbricals m : 3 and 4

Answer 11

medial 3 tendons of flexor digitorum profundus (bipennate muscles)
extensor expansion of fingers 2-5
deep branch of ulnar nerve
C8, T1
flex MCP joints, extend IP joints of fingers 2-5

Question 12

Dorsal interossei m. 1-4

Answer 12

adjacent sides of 2 MCs (bipennate muscles)
bases of proximal phalanges, extensor expansion fingers 2-4
deep branch of ulnar nerve
C8, T1
abduct fingers 2-4 from axial line, assist lumbricals in flexing MCP joints and extending IP joints

Question 13

Palmar interossei m. 1-3

Answer 13

palmar surfaces of MC 2, 4, 5 (unipennate)
bases of proximal phalanges, extensor expansion of fingers 2, 4, 5
deep branch of ulnar nerve
C8, T1
adduct fingers 2, 4, 5 toward axial line, assist lumbricals in flexing MCP joints and extending IP joints